RU2695376C2 - Tube for medical container - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: group of inventions refers to medicine, particularly to a tube for a medical container. Tube for connection to a medical container comprises a tube wall consisting of at least two layers. At least one layer contains a styrene-containing thermoplastic polymer, an ester copolymer, a copolymer of complex and ethers or a cycloolefin copolymer, wherein the styrene-containing thermoplastic polymer is selected from a block copolymer of styrene and butadiene (SBC), polystyrene-polybutadiene-polystyrene (SBS), polystyrene-polyisoprene-polystyrene (SEPS), polystyrene-isoprene/butadiene-polystyrene (SEEPS) and a block copolymer of moly methyl methacrylate-polybutadiene-polystyrene (MBS). At least one other layer contains a copolymer of ethylene and vinyl acetate (EVA), transparent thermoplastic polybutene and/or polystyrene-polyethylene butylene-polystyrene (SEBS). Group of inventions also relates to a medical container containing a nozzle from said tube.

EFFECT: group of inventions provides a tube for a medical container, which has improved connectivity, particularly adhesion, and is flexible.

15 cl, 3 dwg, 2 tbl

Description

FIELD OF TECHNOLOGY

The present invention relates to a tube for a medical container according to the generic concept of claim 1, in particular to a tube with a tube wall that consists of at least two layers.

A tube for a medical container, hereinafter also referred to as a medical tube, is characterized in that the tube is flexible, soft and transparent, and in that it does not break when carried around roundings or when bent, and the lumen of the tube does not overlap at the inflection point. Another important property of a medical tube is that the tube restores its shape reliably and reliably after compression. The latter property can be explained by good elasticity or good recovery properties after deformation, and it is also called “good shape recovery”. This property is especially important when using a medical tube in conjunction with pump systems that deform the tube. The scope of such tubes is, in particular, parenteral or enteral nutrition of patients.

BACKGROUND OF THE INVENTION

For many decades, medical tubes have been widely used that contain a substantially uniform tube wall made of polyvinyl chloride (PVC; from English: polyvinyl chloride) with plasticizers incorporated therein. The advantages of these PVC tubes with plasticizers are low-cost production due to the easy availability of the starting materials and the fact that these tubes are transparent and have good recovery properties after deformation. Without the addition of plasticizers, polyvinyl chloride as such would be too hard to be used in a medical tube. The disadvantage of such tubes is that in recent years, the plasticizers commonly used in PVC are suspected of being harmful to human health. As another disadvantage of these tubes, it can be noted that when they are destroyed by burning, hydrochloric acid is formed and, depending on thermal conditions, dioxins are also formed. Therefore, such destruction in itself is not safe for the environment, and it must be carried out under conditions with special protection, which increases the cost of liquidation.

As part of further development, for the manufacture of tubes that are environmentally friendly when they are destroyed, tubes that do not contain substances harmful to health, in particular carcinogens, tubes are proposed in EP 0355711, the wall of which consists of a homogeneous copolymer of ethylene and vinyl acetate (EVA; from English .: ethylene-vinyl acetate) with a share of vinyl acetate (VA; from the English: vinyl acetate), lying in the range from 12% to 28%. These so-called EVA monotubes, used as an alternative to PVC tubes, are transparent, soft and flexible and have good recovery properties after deformation (“good shape recovery”). In addition, these EVA monotubes can be reliably connected to medical containers if these containers or the tube connecting elements attached to them are also made of ethylene vinyl acetate. Namely, the medical tube can easily be soldered to the container or its connecting element. A drawback of EVA monotubes is that EVA, due to its chemical inertness, cannot be glued, in particular using standard solvents, with materials commonly used for medical containers. This includes materials used for connectors or connectors, which typically include acrylonitrile butadiene styrene (ABS; acrylonitrile-butadiene-styrene), polycarbonate (PC; polycarbonate), polyvinyl chloride (PVC) polymethylmethacrylate (PMMA; from English: polymethylmethacrylate), ester copolymers, ester copolymers, thermoplastic polyurethane (TPU; from English: thermoplastic polyurethane), or combinations thereof. For the manufacture of medical tubes that adhere well to these materials, DE 19504414 proposed medical tubes whose wall has a structure of at least two layers, the outer layer containing ethylene vinyl acetate (EVA) and the inner layer containing polyurethane (PU ; from English: polyurethane). In these two-layer tubes, the inner layer of polyurethane serves as an adhesive element, since it ensures that the proposed tube can be easily glued by sliding onto a conical connector of a medical container made of one of the above commonly used materials. The disadvantage of double-layer tubes with a polyurethane layer as an adhesive layer is that this tube is relatively more expensive to manufacture than standard PVC tubes with plasticizers. A further disadvantage is that this tube is only suitable for connection to a conical connector by sliding onto this connector.

US 8178647 B2 discloses medical multilayer tubes that comprise an outer layer comprising Ecdel 9966, an EVA middle layer and an inner layer of low density polyethylene (LDPE; English: low density polyethylene). Although these tubes have good adhesive properties and can be connected to connectors, they are still too hard and therefore poorly suited for use as medical tubes.

In general, in the standard technique for joining tubes and medical containers, two joining methods are known. According to the first method, the container contains a connector (connecting element), made in the form of a cone, or a conical connector, on which you can slide the medical tube. In a typical case, when the tube is pushed onto the conical connector, a solvent is used as a lubricant, and the pushed tube contains an inner surface layer that softens under the action of the solvent. The adhesion of the tube or its gluing to the conical connector after pushing can be improved by stretching the tube in the longitudinal direction. Due to the longitudinal extension of the tube, the diameter of the tube decreases, so that the inward pressure on the conical connector increases. According to a second method for connecting a medical container and a medical tube, the container comprises a connector made in the form of a connecting nozzle, and the tube can be pushed into the distal opening of the nozzle. This second method essentially entails that good bonding or sealing is provided between the outer surface of the tube and the inner surface of the connecting fitting of the connector. Since the elongation of the tube does not occur with this joining method, it is necessary that the outside of the tube has good solubility in a solvent or adhesive, and thereby provide a connection with the material on the inside of the connecting fitting.

The basis of the present invention is the manufacture of a tube for a medical container, which would have improved connectivity, in particular - bonding, and which would be flexible.

To solve this problem, a tube is proposed for a medical container, and this tube has a tube wall, which consists of at least two layers. According to the present invention, at least one layer comprises a styrene-containing thermoplastic polymer (S-TPE; from styrene-containing thermoplastic polymer), an ester copolymer, an ester copolymer or a cycloolefin copolymer (COC; from cycloolefine copolymer) .

Thermoplastic elastomers (linear elastomers; TPE; from the English: thermoplastic elastomer) are polymeric materials that at room temperature behave comparable to classical elastomers, but when supplied with heat, they can plastically deform and thus exhibit thermoplastic properties. Thermoplastic elastomers are materials in which elastic polymer chains are incorporated into a thermoplastic material. Despite the fact that there is no need for chemical crosslinking by vulcanization, which requires time and elevated temperature, as in the case of elastomers, parts made of thermoplastic elastomers, due to their special molecular structure, have rubber-like elastic properties.

Depending on the internal structure, TPEs are often divided into block copolymers and elastomeric alloys. Block copolymers contain hard and soft segments inside the molecule, such as styrene-butadiene-styrene block copolymers (SBC; from English: styrene-butadiene block copolymer). In contrast, elastomeric alloys are mixtures, that is, physical mixtures of finished polymers. Due to various proportions of the mixture and additives, it is possible to obtain a material with the desired properties, for example, a polyolefin elastomer consisting of polypropylene and natural rubber. Depending on the proportion, hardness can be adjusted over a wide range.

Styrene-containing thermoplastic polymers (S-TPE; from the English: styrene-containing thermoplastic elastomer) can in principle be in the form of block copolymers or elastomeric alloys, as described above.

In a preferred embodiment of the present invention, the styrene-containing thermoplastic polymer (S-TPE) may be a block copolymer of styrene and butadiene (SBC). An example of such an SBC is, as described below, polystyrene-butadiene-polystyrene (SBS; from English: styrene-butadiene-styrene). SBC can be purchased easily and inexpensively, for example, from BASF under the trade name Styroflex ^® , preferably Styroflex is used with the product name 2G 66. In English, the designation "SBC" is used, while in German the designation "SBS (from it. : Styrol-Butadien-Styrol) ”or“ SEBS (from it: Styrol-Ethylen-Butadien-Styrol) ”.

In the present invention, styrene-containing block copolymers are particularly preferred, with the other blocks consisting of polybutadiene, polyethylene butylene, polyisoprene and a copolymer of polyisoprene and butadiene. Examples of such S-TPEs are polystyrene-butadiene-polystyrene block copolymers (SBS), polystyrene-polyethylene butylene-polystyrene (SEBS), polystyrene-polyisoprene-polystyrene (SEPS), polystyrene-polyisoprene / butadiene-polystyrene (SEE-polystyrene polymethylene polyethylene (MBS). However, in this case one block, for example, a polybutadiene block in SBS, can be replaced by a random copolymer of styrene and butadiene. The S-TPEs of the present invention are also not limited to pure block copolymers.

) и этиленгликоля (EG; от англ.: ethyleneglycol), посредством встраивания других мономеров, таких как изофталевая кислота (IPA; от англ.: isophtalic acid) или циклогександиметанол (CHDM; от англ.: cyclohexanedimethanol), может быть преобразован в другой сополимер сложных эфиров, например - полициклогексилендиметилентерефталат (TPS+CHDM-EG). Сополимеры сложных эфиров, как правило, имеют хорошие свойства в отношении прочности, прозрачности и других механических свойств, таких как превосходная вязкость, гидролитическая стабильность, термостойкость и устойчивость против химических веществ, которые обычно влияют на полимеры, например - на поликарбонаты. Сложным полиэфиром, используемым в настоящем изобретении, является Tritan МХ710 производства компании Eastman, который обладает указанными выше свойствами.Ester copolymers are formed when polyesters are modified, which, in turn, are combinations of dibasic acids and diols. As an example, the well-known polyethylene terephthalate (PET; from English: polyethylene terephtalate), which is obtained from terephthalic acid (TPS; from it:

) and ethylene glycol (EG; from English: ethyleneglycol), by embedding other monomers such as isophthalic acid (IPA; from English: isophtalic acid) or cyclohexanedimethanol (CHDM; from English: cyclohexanedimethanol), can be converted to another copolymer esters, for example polycyclohexylene dimethylene terephthalate (TPS + CHDM-EG). Copolymers of esters, as a rule, have good properties with respect to strength, transparency and other mechanical properties, such as excellent viscosity, hydrolytic stability, heat resistance and resistance to chemicals that usually affect polymers, for example polycarbonates. The polyester used in the present invention is Eastman Tritan MX710, which possesses the above properties.

The copolymers of esters and ethers contain a segment of a complex polyester and a segment of a simple polyester. The copolymers of esters and ethers have good properties, such as transparency, viscosity and high chemical resistance. The segment of the polyester has the composition indicated above, that is, it can be a polyester, such as PET, or a corresponding copolymer of esters. The polyester segment consists of a polyester (including polyalkylene glycol, polyester polyol, polyalkylene oxide) or polyester polyol. Examples of polyethers are polyethylene glycol (PEG; from English: polyethyleneglycol) and polypropylene glycol (PPG; from English: polypropyleneglycol), which can be obtained by catalytic polymerization of the corresponding epoxides (oxiranes) of ethylene oxide or propylene oxide. Suitable polyether polyols can be prepared by reacting epoxides with diols. In addition to diols, polybasic alcohols can also be converted to polyether polyols, for example glycerol, 1,1,1-trimethylolpropane (TMP; from English: trimethylolpropane), pentaerythritol or sorbitol in the reaction with epoxides in the presence of strong bases (for example, KOH). The polyether moiety may also be a block copolymer, which is obtained by sequential polymerization with various epoxides. Well-known polyether polyols are Lupranol (manufactured by BASF SE) and Desmophen (manufactured by Bayer Material Science). Also epoxy terminated polyethers are epoxies. However, ester and ether copolymers preferred in the present invention are those which consist of a simple polyester and a simple polyester. An example of such an ester copolymer useful in the present invention is Ecdel 9967 from Eastman.

Cycloolefin copolymers (SOC) are copolymers containing olefin monomers, for example, ethylene, and cycloolefin monomers, for example, norbornene. Norbornene is obtained, for example, from cyclopentadiene and ethylene. The copolymerization reaction is usually catalyzed by metallocenes and leads to the formation of random copolymers. Although SOSs consist solely of olefins, but unlike partially crystalline polyolefins, such as polyethylene and polypropylene, they are amorphous and therefore transparent. The properties of the SOS can be changed in a wide range by changing the ratio of the included cyclic and linear polyolefins. For example, if a large amount of norbornene is used, then it suppresses crystallinity and results in hard polymer chains. However, flexible amorphous copolymers can also be obtained due to the low norbornene content of less than 20 mol. % Flexible semi-crystalline copolymers can be obtained due to the low content of norbornene, which is less than 15 mol. % Essentially, you can adjust the dimensional stability when heated in the range from 65 ° C to 190 ° C. All SOS together have a number of properties, such as good thermoplastic fluidity, high stiffness, strength and hardness, as well as low density and high transparency with good resistance against acids and alkalis. The cycloolefin copolymer used in the present invention is TOPAS Elastomer E-140 manufactured by Topas Advanced Polymers.

If S-TPE, an ester copolymer, an ester copolymer or a cycloolefin copolymer are used for the layer, they give the layer good adhesion, in particular good adhesion to materials, which are typically used to make medical containers or connectors attached to them such as ABS, PC, PVC, PMMA, ester copolymers, ester copolymers, thermoplastic polyurethane (TPU) or mixtures of these substances.

With a suitable choice of material of another layer, for example, EVA, such a tube is not more expensive to manufacture than PVC tubes with plasticizers. In addition, to improve the recovery properties after deformation, EVA can be mixed with TPE (for example, with a SEBS copolymer) (compound). In addition, such a tube does not contain PVC and plasticizers and, therefore, upon destruction it is safe for the environment and is not hazardous to health or carcinogenic.

Preferably, the tube contains at least one layer that contains a copolymer of ethylene and vinyl acetate (EVA). In particular, this layer is not the same layer that contains a styrene-containing thermoplastic polymer, an ester copolymer, an ester copolymer or a cycloolefin copolymer. A tube containing a layer containing S-TPE, an ester copolymer, an ester copolymer or a cycloolefin copolymer, and an EVA layer are not more expensive to manufacture than commonly used PVC tubes with plasticizers, and do not contain PVC and plasticizers.

The proportion of vinyl acetate (VA) in the copolymer of ethylene and vinyl acetate is from 10 mass. % to 30 mass. %, preferably from 14 wt. % to 28 mass. % Due to the choice of this material, the tube is insensitive to temperature changes and has good mechanical properties, for example, good recovery properties after deformation.

In an embodiment of the present invention, in which at least one layer contains a copolymer of ethylene and vinyl acetate (EVA), this layer (optionally) may contain transparent thermoplastic polybutene or, optionally, SEBS. Thermoplastic polybutene or SEBS can be added to this layer as an additive with a fraction lying in the range from 1 mass. % to 50 mass. %, preferably from 10 mass. % to 20 mass. %

The tube can be made so that the outer of at least two layers contains a styrene-containing thermoplastic polymer (for example, Styroflex 2G 66 manufactured by Styrolution), a copolymer of polyesters (for example, Tritan MX710 manufactured by Eastman), a copolymer of esters and ethers (for example, Ecdel 9967 from Eastman) or a cycloolefin copolymer (e.g. Topas ^® Elastomer from Topas Advanced Materials). Such a tube is suitable for connection with a medical container according to the second connection method, that is, by sliding into the connector of the medical container, made in the form of a connecting fitting.

Alternatively, the tube may be configured such that the inner layer of the at least two layers comprises a styrene-containing thermoplastic polymer, a polyester copolymer, an ester and ether copolymer, or a cycloolefin copolymer. Such a tube is suitable for connection with a medical container according to the first connection method, that is, by pushing the tube over the conical connector of the medical container.

Preferably, the layer comprising a styrene-containing thermoplastic polymer, a copolymer of polyesters, a copolymer of esters and ethers or a cycloolefin copolymer has a thickness that is less than the thickness of another layer of at least two layers of the tube. With a suitable choice of material of another layer, for example EVA, the tube has good mechanical properties, in particular, good elasticity. In addition, a relatively thinner layer containing a styrene-containing thermoplastic polymer, a polyester copolymer, an ester copolymer or a cycloolefin copolymer is well suited for bonding between this layer and materials that are commonly used to make medical containers or the connectors provided thereon, such such as acrylonitrile butadiene styrene (ABS), polycarbonate (PC), polyvinyl chloride (PVC), polymethyl methacrylate (PMMA), ester copolymer, ester copolymer, term plastic polyurethane (TPU) or combinations of these materials.

Alternative to the two-layer structure, the tube wall may consist of at least three layers, the outer and inner layers of at least three layers containing a styrene-containing thermoplastic polymer, a copolymer of polyesters, a copolymer of esters and ethers or a cycloolefin copolymer. A tube made in this way is suitable for bonding both with a connector made in the form of a connecting fitting and with a connector made in the form of a cone. A tube made in this way can also be used as an adapter for connecting the ends of two tubes with different diameters, or for connecting a tube to a conical connector if the outer diameter of the connector is less than the inner diameter of the tube, or for connecting the tube to a connector made in the form of a connecting fitting, if the inner diameter of the connector is larger than the outer diameter of the tube.

In a tube containing at least three layers, each of the outer and inner layers containing a styrene-containing thermoplastic polymer, a copolymer of polyesters, a copolymer of esters and ethers or a cycloolefin copolymer may have a thickness that is less than the thickness of the middle layer of at least three layers . In this case, the same advantages are achieved as in the case of a tube with a two-layer wall structure and a thinner layer containing S-TPE compared to the thickness of the other layer.

A layer containing a styrene-containing thermoplastic polymer, a copolymer of polyesters, a copolymer of esters and ethers or a cycloolefin copolymer may have a thickness ranging from 0.01 mm to 0.3 mm Such a small thickness is already sufficient to ensure good adhesion with the TPE contained in the layer. In addition, the feed rate (feed rate) of the S-TPE is small compared to the material of another relatively thicker layer of the tube.

The tube may have an inner diameter (D _i ) lying in the range from 1.0 mm to 6.0 mm with a tolerance of ± 0.1 mm. In particular, the tube may have an inner diameter of 3.0 mm or with a tolerance of ± 0.1 mm. Such a tube is suitable for use with commercially available and standardized conical connectors corresponding to its size, in particular the outer diameter.

The tube may have an outer diameter (D _a ) ranging from 2.0 mm to 8.0 mm with a tolerance of +0.1 mm and -0.3 mm. In particular, the tube may have an outer diameter of 4.10 mm with a tolerance of +0.1 mm and -0.3 mm. Such a tube is suitable for use with commercially available and standardized connectors made in the form of connecting fittings.

The tube may have a total wall thickness ranging from 0.3 mm to 1.0 mm with a tolerance of ± 0.05 mm. In particular, the tube may have a wall thickness of 0.55 mm with a tolerance of ± 0.05 mm. A tube made in this way has the same advantageous mechanical properties as the widely used, in particular standardized, PVC tubes with plasticizers.

The tube can be made by co-extrusion (coextrusion). In this case, the tube is manufactured using a one-step and therefore relatively cheap manufacturing method.

According to another aspect of the present invention, there is provided a medical container, in particular a container for enteral or parenteral nutrition. According to the present invention, the container comprises at least one nozzle from the tube of the present invention described above.

The container may be made of a material that contains a copolymer of ethylene and vinyl acetate (EVA), and the nozzle may be welded or glued to the outer layer of the tube, which, being the outer of at least two layers, contains a styrene-containing thermoplastic polymer, a copolymer of polyesters, a copolymer esters and ethers or cycloolefin copolymer.

Alternatively, the medical container may be made of a material that contains a copolymer of ethylene and vinyl acetate (EVA), the container containing a conical connecting element onto which the tube can be pulled by its inner layer containing a styrene-containing thermoplastic polymer, a copolymer of polyesters, a copolymer of complex and simple esters or cycloolefin copolymer.

Two exemplary embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. The following is depicted:

FIG. 1 is a cross-section through a first embodiment of a tube of the present invention;

FIG. 2 is a cross-section through a second embodiment of a tube of the present invention; and

FIG. 3 is a cross-section through a third embodiment of a tube of the present invention;

In FIG. 1 and FIG. 2 shows, respectively, the tube 10 and the tube 10 'with a two-layer structure of the tube wall. Depicted in FIG. 1, a tube 10 according to a first embodiment of the present invention comprises an outer layer 12 that contains a styrene-containing thermoplastic polymer, an ester copolymer, an ester copolymer or a cycloolefin copolymer, and an inner layer 14 that contains a material different from the material of the outer layer 12. Outer layer 12 can also be completely made of a styrene-containing thermoplastic polymer, for example, from a styrene-butadiene block copolymer (SBC), an ester copolymer, a co-polymer zhnyh and ethers, or cycloolefin copolymer. The inner layer 14 is made of a material other than polyvinyl chloride (PVC) and polycarbonate (PC), and preferably ethylene-vinyl acetate (EVA) with a proportion of vinyl lying in the range from 10 mass. % to 30 mass. %, preferably from 14 wt. % to 28 mass. %

Depicted in FIG. 2, the tube 10 'according to the second embodiment of the present invention contains an outer layer 14', which is made of a material different from PVC, PC and S-TPE, and an inner layer 16, which contains a styrene-containing thermoplastic polymer, an ester copolymer, an ester copolymer esters or cycloolefin copolymer. To the materials contained in the inner layer 16 or the outer layer 14 'of the tube 10' according to FIG. 2, respectively, applies the same as described above for the materials contained in the outer layer 12 or in the inner layer 14 of the tube 10 according to FIG. one.

The outer layers (layer 12 in FIG. 1 and layer 14 in FIG. 2) and the inner layers (layer 14 in FIG. 1 and layer 16 in FIG. 2) ensure uniform wall thickness. The outer surface of the corresponding inner layer of the tube 10 in FIG. 1 and tubes 10 'in FIG. 2 over its entire area is in contact with the inner surface of the corresponding outer layer.

The outer surface and inner surface of the corresponding inner layer and the outer surface and inner surface of the corresponding outer layer have a circular cross section. In addition, they are located coaxially with the coincident centers of the cross sections. The tubes 10 (in FIG. 1) and 10 '(in FIG. 2) are made by coextrusion, so that the corresponding outer layer and the corresponding inner layer are firmly connected to each other. The tubes 10 or 10 'are sterilized at least on the inner surface 24 or 26 of the corresponding inner layers 14 or 16 of the tubes 10 or 10' and preferably also on the outer surfaces 20 or 22 of the corresponding outer layers 12 or 14 ', for example by treatment with ethylene oxide or by radiation sterilization.

Depicted in FIG. 3, a tube 10 ″ according to a third embodiment of the present invention comprises a tube wall with a three-layer structure. The wall of the tube contains an outer layer 12, which contains a styrene-containing thermoplastic polymer, an ester copolymer, an ester copolymer or a cycloolefin copolymer, a middle layer 14 '', which contains a material other than PVC, PC and S-TPE, and an inner layer 16 which contains a styrene-containing thermoplastic polymer, an ester copolymer, an ester copolymer or a cycloolefin copolymer. The materials of the outer layer 12 and the inner layer 16 are the same as described above for the outer layer 12 of the tube 10 according to FIG. 1 and for the inner layer 16 of the tube 10 'according to FIG. 2. To the material of the middle layer 14 ″ of the tube 10 ″ according to FIG. 3 refers to the same as described above for the material of the inner layer 14 of the tube 10 shown in FIG. 1 and the material of the outer layer 14 ′ of the tube 10 ′ shown in FIG. 2.

In a preferred embodiment of the present invention, a product commercially available from BASF under the trade name Styroflex with the product name 2G 66 is preferably used as styrene-containing thermoplastic polymer (S-TPE). In another preferred embodiment of the present invention, a product is used as an ester copolymer. commercially available from Eastman, with the product name Tritan MX710 or, alternatively, a copolymer of esters and ethers with the product name Ecdel 9967 manufactured by Eastman. In a further preferred embodiment of the present invention, Topas ^® Elastomer COC manufactured by Topas Advanced Materials is used as the cycloolefin copolymer.

In tube embodiments in which at least one layer contains a copolymer of ethylene and vinyl acetate (EVA), transparent thermoplastic polybutene (e.g., product named Koattro KT AR05 manufactured by Basel) or SEBS (e.g., Kraton G1652 manufactured by Kraton). Moreover, the mass fraction of polybutene or SEBS can be from 1% to 50%, preferably from 10% to 20%, more preferably 2%, and even more preferably 5%.

In serial experiments, it was found that by adding thermoplastic polybutene or SEBS as an additive to EVA in general

- the incidence of breaks decreases;

- the properties of the tube with respect to bending properties (including “shape restoration”) become more similar to the properties of PVC tubes, which is desirable since PVC tubes are considered standard in the art and new designs of medical tubes are compared with PVC tubes;

- increased elasticity, so that the tube becomes easier to reel (which is preferable, since the tube for transportation in the form of numerous (O-shaped) turns is wound on the feed or transport spools);

- and finally, the pronounced "shape memory" (the term "memory" is used in the technical field) of tubes from EVA (that is, from EVA without adding additives) (which occurs, for example, when using a new (fresh) tube due to radius bending spool used during transportation).

The outer layer 12, the middle layer 14 ″ and the inner layer 16 have a uniform thickness. The outer surface of the inner layer 16 over the entire area is in contact with the inner surface 24 of the middle layer 14 ″, and the outer surface 22 of the middle layer 14 ″ over the entire area is in contact with the inner surface of the outer layer 12. The outer surfaces and inner surfaces of each the inner, middle and outer layers have a circular cross section. They are located coaxially, that is, with matching centers of the cross sections. The tube 10 ″ is made by coextrusion, so that the outer layer 12 is firmly connected to the middle layer 14 ″ and the inner layer 16 is firmly connected to the middle layer 14 ″. The tube 10 ″ is sterilized on the inner surface 26 of the inner layer 16 and preferably also on the outer surface 20 of the outer layer 12, for example by treatment with ethylene oxide or by radiation sterilization.

In the case of tubes 10, 10 ', 10''shown in Figures 1 to 3 according to embodiments of the present invention, the first to third inner diameter D _i is 3.0 mm with a tolerance of ± 0.10 mm, the outer diameter D _a equal to 4.10 mm with a tolerance of +0.10 mm and -0.30 mm, and the thickness W ₁₂ , W ₁₆ layers 12, 16 containing S-TPE, lies in the range from 0.01 mm to 0.30 mm

The infusion device not shown in the Figures comprises a medical container and a connecting medical tube leading to the patient. The medical container contains a bag with a connector for connecting a medical tube. The package consists of a copolymer of ethylene and vinyl acetate and is filled with a fat-containing nutrient solution, for example, for the patient's enteral or parenteral nutrition.

In an embodiment of the present invention, the container comprises a connector made in the form of a connecting fitting. The container is made of a copolymer of ethylene and vinyl acetate, and the connector is made of acrylonitrile butadiene styrene (ABS), polycarbonate (PC), polyvinyl chloride (PVC), polymethyl methacrylate (PMMA), ester copolymer, ester copolymer, thermoplastic polyurethane (TPU) or combinations thereof. The connector is made in the form of a connecting fitting into which a medical tube can be inserted or inserted. The tube is made as shown in FIG. 1 of a first embodiment of the present invention or as shown in FIG. 3 to a third embodiment of the present invention and comprises, on its outer side, a layer 12 comprising S-TPE. Layer 12 of a 10 or 10 '' tube is glued to the inside of the connecting fitting, namely using commercially available solvents such as, for example, cyclohexanone (CHEX; from the English: cyclohexanone), tetrahydrofuran (THF; from the English: tetrahydrofuran), methyl ethyl ketone (MEK; from the English: methyl ethyl ketone) or a mixture of these substances (for example, a mixture of MEK / CHEX). Alternatively, the layer 12 of the tube 10 or 10 ″ may be welded to the inside of the connecting fitting.

In another embodiment of the present invention, the connector is cone-shaped and a tube 10 ′ is pulled over the cone-shaped connector as shown in FIG. 2 to the second embodiment or tube 10 ″ according to FIG. 3 to a third embodiment of a medical tube of the present invention. Before pushing the tube, a commercially available solvent is applied to the inner surface of the tube 10, 10 ′ and / or to the outer surface of the conical connector, which acts as a lubricant when the tube is pushed. After the tube is pulled onto the connector, the tube is stretched in the longitudinal direction at least in the portion pulled onto the connector, so that elastic, radially inwardly directed stress or radially inwardly directed compressive pressure is applied to the outer surface of the conical connector. Under the influence of the solvent, the inner layer 16 of the tube 10 'or 10' 'and the outer surface of the conical connector are dissolved and firmly connected to each other by gluing. Alternatively, the outside of the conical connector may be welded to the inner layer (16) of the tube (10 ′, 10 ″).

For the manufacture of tubes 10, 10 ', 10''according to the first, second or third embodiments of the present invention, both main substances are fed separately to the coextrusion machine — an ethylene vinyl acetate copolymer or, alternatively, a polymer mixture of EVA and thermoplastic polybutene and / or SEBS in the form of solids, as well as the outer and / or inner layer of a styrene-containing thermoplastic polymer (e.g. Styroflex 2G 66 manufactured by Styrolution), an ester copolymer (e.g. Tritan MX710 manufactured by East man), a copolymer of ethers and esters (for example, Ecdel 9967 manufactured by Eastman) or a cycloolefin copolymer (for example, Topas ^® Elastomer manufactured by Topas Advanced Materials), in particular in the form of a granulate. The basic substances are individually heated and compacted using an extruder device, for example, an extruder screw. The heated and flowing masses are separately fed into the nozzle of the extrusion press, from which they in the first embodiment of the present invention come out in the form of a tube 10 with an inner layer of EVA and an outer layer of S-TPE, an ester copolymer, an ester copolymer or COC, in a second embodiment of the present invention, in the form of a tube 10 'with an outer layer 14' of EVA and an inner layer 16 of S-TPE, and in a third embodiment of the present invention, in the form of a tube 10 'with an outer layer 12 and an inner layer 16 from S-TPE, with ester polymer, ester copolymer or COC and EVA 14 '' middle layer.

EXPERIMENTAL PART

The materials for tubes intended for connection to a medical container described in this publication were tested in gluing experiments, their bending strength was evaluated, and compared with each other.

Determination of bending strength

In this series of experiments, the deflection or elasticity of the tubes at a given load was determined. To do this, a TS device for determining the flexural strength manufactured by FRANK-PTI was used.

In the experiments described below (see Table 1), tubes made of the following materials and material combinations were used.

In series 1 of the experiments, PVC as such was tested. The PVC used was soft PVC with shore hardness A 80, plasticizer was DINCH manufactured by BASF SE.

In a series of 2 experiments, LDPE / S-TPE was used as the material for the two-layer tube. The LDPE used was Basell's Purell PE 1840 polyethylene, S-TPE was Styroflex 26 66 manufactured by Styrolution.

In a series of 3 experiments, an EVA / ester copolymer was used as the material for the two-layer tube. The EVA used was Evathane 28.05 from ARKEMA, the copolymer of esters and ethers was Ecdel 9967 from Eastman.

In a series of 4 experiments, EVA / PET was used as the material for the two-layer tube.

In a series of 5 experiments, soft PP was used as the tube material. The soft PP used was a mixture of a random polypropylene copolymer and a hydrogenated block copolymer of styrene and isoprene.

In a series of 6 experiments, only EVA was used as the material for the tube.

Standard materials used in medical technology were tested as connector materials - solid PVC (Nakan RMA705N T01, control), polycarbonate (Makrolon Rx 1805) and ester copolymer (Tritan MX 731).

In each series of experiments, 10 tubes were tested, each of which had a length of approximately 10 cm. The test was carried out after storage for 72 hours under climatic conditions similar to the Shore A test (ISO 868). Samples were clamped in the clamping device provided, with approximately 1 cm of the tube protruding backward from the clamping device and most of the tube protruding forward.

Test conditions or set parameters were as follows:

23 ° С ± 1 ° С room temperature

Measurement Accuracy ± 1%

Test speed 6 ° / s

Angle: 30 ° (value of the final angle)

Hold time: 2 s

Preliminary force: 0.005 N

Test distance: 30 mm

The measurement results were obtained as the value of the maximum measured force (N), and the measurements were repeated until 10 measurement results were obtained from which the average value was calculated.

Determination of peel force in tensile test

In this series of experiments, the separation force was determined in [N] in a tensile test.

The tube materials used were the same materials as in the determination of bending strength.

Various tubes using the described solvents (tetrahydrofuran (THF) or a mixture of methyl ethyl ketone (MEK) and cyclohexanone (CH or CHEX) were glued to various parts and were stored at room temperature for 5 days before tensile experiments until the solvents completely evaporated.

In this case, the test samples were various parts that were glued to the tube. A Zwick tensile testing machine was used as a measuring instrument.

The speed during the test was 200 mm / min, the distance between the grips depended on the test sample.

RESULTS

The EN 1615/1618 standard states that bending strength is sufficient if it is 15 N. However, this value was considered too low in this work. Therefore, in this present work, we tried to reach the tensile strength at least 2 times higher than this norm, that is, at least 30 N.

The material has sufficient adhesive properties, for example, if a tear-off force of at least 35 N is required. A lower tear-off force of, for example, 20 N indicates insufficient connection stability between the tube and the connector.

A material has good elasticity if it has a bending strength of less than about 0.7 mN. Materials with higher flexural strength are generally too hard and unsuitable for use as a tube for medical containers.

It was found that the commonly used PVC, although it has good adhesive properties, is too hard and, in addition, as described above, has other disadvantages, for example, the plasticizers contained therein and insufficient environmental safety (see Tables 1 and 2 , a series of 1 experiments).

If, on the contrary, a transparent EVA tube (monotube) is used, then fixation on the connector is insufficient, which was shown in gluing experiments (see Table 1, series 7 experiments).

The use of soft PP also proved unsatisfactory in terms of adhesive properties (see Table 1, series 6 experiments).

Additionally, various combinations of materials were compared with each other. The combination of LDPE and a styrene-containing thermoplastic polymer (Styroflex 2G 66) leads, although to good adhesive properties (see Table 1, series 2 experiments), but to insufficient flexibility (see Table 2, series 2 experiments).

All combinations

- EVA with a copolymer of esters and ethers (Tables 1 and 2, series 3 experiments),

- EVA with styrene-containing thermoplastic polymer (Tables 1 and 2, series 4 experiments), and

- EVA with ester copolymer (Tables 1 and 2, series 5 experiments) have good elastic properties and at the same time exhibit good adhesion to the materials of the connectors.

Instead of EVA, thermoplastic polybutene and / or SEBS can also be used.

Based on the experiments, it was also shown that the tubes of the present invention with at least two layers, with one layer consisting of S-TPE, an ester copolymer or an ester copolymer, have the desired properties of good adhesion and high elasticity. Also, cycloolefin copolymers demonstrated good properties in experiments not shown in this publication.

Notation list

10 handset

10 'tube

10 '' Tube

12 S-TPE outer layer

14 EVA Layer

14 'Layer from EVA

14 '' EVA layer

16 Inner layer of S-TPE

20 Outer surface (outer layer 12)

22 Outer surface (layers 14, 14 ', 14``)

24 Inner surface (layers 14, 14 ', 14``)

26 Inner surface (inner layer 16)

D _i Inner Diameter

D _a Outer diameter

W ₁₂ Layer Thickness 12

W ₁₄ Layer Thickness 14

W _{14 '} Layer thickness 14'

W _{14 ''} Layer Thickness 14 ''

W ₁₆ Layer thickness 16.

Claims (15)

1. A tube (10; 10 '; 10``) for connecting to a medical container with a tube wall that contains at least two layers (12, 14; 14, 16), characterized in that at least one layer (12 ; 16) contains a styrene-containing thermoplastic polymer, a copolymer of esters, a copolymer of esters and ethers or a cycloolefin copolymer, and at least one layer (14, 14 ', 14' ') contains a copolymer of ethylene and vinyl acetate (EVA), a transparent thermoplastic polybutene and / or polystyrene-polyethylene butylene-polystyrene (SEBS), and styrene-containing thermoplastic The first polymer is selected from styrene-butadiene block copolymer (SBC), polystyrene-polybutadiene-polystyrene (SBS), polystyrene-polyisoprene-polystyrene (SEPS), polystyrene-isoprene / butadiene-polystyrene (SEEPS), and polymethyl-polystyrene-polybutene (MBP) block copolymer . 2. The tube according to claim 1, characterized in that the mass fraction of vinyl acetate (VA) in the copolymer of ethylene and vinyl acetate (EVA) lies in the range from 10 to 30%, preferably from 14 to 28%. 3. Tube (10) according to claim 1, characterized in that during its manufacture at least one layer (14, 14 ', 14``), thermoplastic polybutene or SEBS is added as an additive in a mass fraction lying in the range from 1 to 50%, preferably 10 to 20%. 4. Tube (10) according to claim 1, characterized in that the outer layer (12) of at least two layers (12, 14) contains a styrene-containing thermoplastic polymer, a copolymer of esters, a copolymer of esters and ethers, or a cycloolefin copolymer. 5. A tube (10 ') according to claim 1, characterized in that the inner layer (16) of at least two layers (14, 16) contains a styrene-containing thermoplastic polymer, an ester copolymer, an ester and ether copolymer or a cycloolefin copolymer. 6. The tube according to claim 1, characterized in that the layer (12; 16) containing a polymer selected from a styrene-containing thermoplastic polymer, a copolymer of esters, a copolymer of esters and ethers or a cycloolefin copolymer, has a thickness (W12; W16), which less than the thickness (W14; W14 ') of the other layer (14; 14') of at least two layers. 7. The tube (10``) according to claim 1, characterized in that the wall of the tube consists of at least three layers (12, 14``, 16), and that the outer (12) and inner (16) layers of at least three layers contain a styrene-containing thermoplastic polymer (S-TPE), an ester copolymer, an ester copolymer or a cycloolefin copolymer. 8. A tube according to claim 7, characterized in that each of the outer and inner layer (12, 16) containing a styrene-containing thermoplastic polymer has a thickness (W12; W16) that is less than the thickness (W14 '') of the other layer (14 ' ') of at least three layers. 9. The tube according to claim 1, characterized in that the layer (12; 16) containing a styrene-containing thermoplastic polymer, a copolymer of esters, a copolymer of esters and ethers or a cycloolefin copolymer, has a thickness (W12; W16) ranging from 0 , 01 to 0.30 mm. 10. The tube according to claim 1, characterized in that the tube has an inner diameter (D _i ) lying in the range from 1.0 to 6.0 mm with a tolerance of ± 0.1 mm. 11. The tube according to any one of the preceding paragraphs, characterized in that the tube has an outer diameter (D _a ) lying in the range from 2.0 to 8.0 mm with a tolerance of +0.1 mm and -0.3 mm. 12. The tube according to claim 1, characterized in that the tube has a total wall thickness lying in the range from 0.3 to 1.0 mm with a tolerance of ± 0.05 mm. 13. A medical container, in particular for enteral or parenteral nutrition, characterized by the presence of at least one nozzle from the tube (10, 10 ', 10``) according to claim 1. 14. The medical container according to claim 13, characterized in that the material the container is made of contains a copolymer of ethylene and vinyl acetate (EVA), and the fact that the container contains a connector made in the form of a connecting fitting, and a tube is inserted into the connecting fitting ( 10, 10``) according to claim 1, and moreover, in particular, the inner side of the connecting fitting is welded or glued to the outer layer (12) of the tube (10, 10``). 15. The medical container according to claim 13, characterized in that the material the container is made of contains a copolymer of ethylene and vinyl acetate (EVA), and that the container contains a conical connector on which the tube is pulled (10 ', 10 '') according to any one of the preceding paragraphs, in particular, according to claim 3, and moreover, in particular, the outer side of the conical connector is welded or glued to the inner layer (16) of the tube (10 ', 10' ').

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